This invention relates to a bulk container, a removable, disposable liner for the container, and means for attaching the liner to an output port on the bulk container.
The bulk container and liner are useful for storing and shipping materials that flow, such as fluids and pulverized solid materials. Such materials, such as fluid adhesives, paints and pulverized foodstuffs, flow out of the container and liner through an opening or port in the bulk container. Typically the materials flow out of the container under the influence of gravity.
Storage and shipment of fluids and pulverized solids can be accomplished using containers varying in size to several hundred gallons. Such containers can be made from a variety of materials. For example, 55 gallon drums constructed of steel have been used extensively. Also, larger bulk containers constructed of roto-molded polyethylene have been used.
Due to the expense of manufacturing and disposal of large containers, it is preferable to reuse the containers as often as possible. However, if material is stored directly inside the container, a number of problems arise. The container must be meticulously cleaned each time it is used in order to avoid contaminating the next batch of material to be stored in the container. Such cleaning may be difficult or even impossible to carry out, depending on the type of material used. Some materials, such as adhesives, may harden and bond to the interior of the container. Cleaning the containers can also prove to be costly, particularly if hazardous or toxic chemicals are used that must be disposed of in accordance with legislated disposal procedures.
In light of these problems, it is generally preferred to use a removable liner in a bulk container to act as a barrier between the stored material and the container wall. Liners can be made from a variety of materials which can be selected based on compatibility with the material to be stored. The liner, being generally made of a lightweight material, can be removed and disposed of after use without contaminating the container. A new liner can then be inserted into the container, and the container can be refilled, without the expensive and time-consuming process of cleaning the container. By using removable liners, a bulk container can be used many times with a large variety of stored materials, and without the need for expensive and time consuming cleaning between uses. This reduces the cost of the bulk container storage and shipment process.
A typical liner includes an inlet fitment (or an open top), and a discharge fitment. The discharge fitment of the liner is adapted to being connected to a discharge coupling on the container. For example, the fitment typically includes a threaded fitting which mates with a threaded fitting on the discharge coupling of the container. Prior art methods of inserting the liner into the container have required that an operator physically enter the container. For example, a bulk container is placed on its side so that a person can climb into the container. The person climbs into the container with a liner in hand, and attaches the discharge fitment of the liner to the discharge coupling on the container or holds it in place while another operator makes the attachment from the outside. The operator then climbs out of the container.
This method is problematic because it requires an operator to be agile, particularly if the container is small. More importantly, if the container previously has been used to store hazardous materials, there is a risk of exposure to such materials. In such a case, OSHA regulations require that specific time-consuming recording procedures be followed, which can significantly slow the process and add greatly to the cost. Accordingly, it is preferable to insert the liner without requiring an operator to enter the container.
A method and apparatus for inserting a liner without the entrance of a person into the container is disclosed in International Application No. PCT/US95/11917. Disclosed therein is a container with a discharge port (essentially a circular hole) in the lower part of one side wall of the container, near the bottom. Fitted to the container at the port is an "adapter assembly", in the form of a pipe with male threads on each end and a permanent flange.
An outlet fitment, which is bonded to a liner, is equipped with female threads and is screwed onto the upstream end of the adapter assembly. The adapter assembly is then inserted into the discharge port until the flange makes contact with the inside of the container wall. A nut is screwed onto the discharge end of the adapter assembly from outside the container, which secures the assembly to the container wall.
In order to guide the adapter assembly with liner attached into the discharge port, a rather complicated method and set of hardware must be used. A plug is screwed into the discharge end of the adapter assembly before it is dropped into the container. The plug has a lanyard attached to it with a magnet on the other end. The magnet is dropped into a "vertical guide tube" until it attaches, through magnetic attraction, to a "horizontal guide tube" which has been inserted into the discharge port so that one end is inside the container and the other is outside the container. The horizontal guide tube is then withdrawn from the container with the magnet (and in turn, the lanyard) attached. The vertical guide tube is then withdrawn and the operator must pull the plug with attached adapter assembly into the container and into the discharge port. Needless to say, this is a complicated process using a number of pieces of large, bulky hardware. In addition, given the fact that the long adapter assembly must be pulled out of a small discharge port from within the container without any guidance, the disclosed system does not allow for the use of a sump in the container, since the adapter assembly would get caught in the sump as it turned from a vertical position to a horizontal position to get into the discharge port. The use of a sump is preferred because it minimizes the amount of material that is left in the container after it is fully drained, thereby minimizing waste.